1. Field of the Invention
The invention concerns a procedure for the draining of sludge, especially of Flocculent flotation sludge, whereby the water-mud cloudiness is introduced into a settling tank with a water overflow.
2. Prior Art
With the use of increasingly productive output machinery in the coal mining industry, the fine and finest granular portion of the raw coal has inevitably increased.
The separation of fine-granular portion of the raw coal is widely effected by flotation. The sludge recovered during the flotation process must be drained to the point that it can be eliminated, i.e, deposited.
The mechanical drainage of the recovered sludge, for example, by swivel filter presses, is connected with high investments and high operating costs.
Therefore, in most cases, the flotation sludge is first thickened by chemical flocculation compounds and the resulting pre-drained sludge is deposited in sink ponds. These ponds provide ample time for the sludge to settle, so that mud-free water flows from the overflow. When the usable space of the sinking pond is filled with mud, a new sinking pond must be constructed.
An essential disadvantage of this procedure is the large area required for the construction of sinking ponds, whereby suitable areas are not always available as needed.
It is, therefore, the task of the presented invention to provide for a simple and economic process for the draining of sludge, especially flocculent flotation sludge, so that it can subsequently be deposited in high containers.